1. Field of the Invention
This invention relates to a system and method for mounting a printed circuit board onto a computer assembly.
2. Background
Printed circuit boards are thin plates on which computer chips and other electronic components are mounted. In recent years, circuit boards have been used extensively in electrical equipment. For example, computers are routinely constructed of a plurality of printed circuit boards, each containing a portion of the electronics required to allow the computer to operate.
A typical circuit board includes an edge connector provided along a leading or forward edge of the board. This edge connector includes electrical contacts which allow the circuit board to communicate with the rest of the computer system. These edge connectors are received in connection sockets located on another circuit board. The amount of force required to seat a circuit board into a connection socket is dependent on the number of contacts and type of electrical connectors used. For a given type of connector, the more contacts that must be mated typically increases the force that must be used to seat the circuit board. In an exemplary circuit board, the three edge connectors require a 100 pound insertion force. Insertion mechanisms have been used to apply an accurate and sufficiently powerful insertion force to an edge of the circuit board opposite the edge connectors. These types of mechanisms are located coplanar to the circuit board, and thus occupy space within the computer housing adjacent to the board edge, which may interfere with access to the internal components.
The computer housings used for state-of-the-art computer systems are often densely filled with multiple circuit boards, media drives, power supplies, cables, and other computer components. Such dense packing significantly increases the difficulty with which these components can be accessed for upgrading and repair. The case of the Power Mac G4 by Apple Computer, Inc. has a swing-open side door that allows easy access to the internal components. In the Power Mac G4, the motherboard and other key components are mounted onto the door, leaving the power supply, media drives, and other non-circuit board components inside the computer housing.
The use of ribbon cables to connect components results in increased cost and decreased performance, as compared to systems using edge connectors; circuit board edge connectors provide higher speed signals and better signal integrity. However, the Power Mac's design uses ribbon cables to enable the door mounting of the circuit board. The ribbon cables are needed to provide a connection between the motherboard and the other system components that can flex to accommodate the opening and closing of the door.